The Clarks' doll experiments grew out of Mamie's master's degree thesis and yielded 3 papers between 1939 and 1940. They found that Black children often preferred to play with white dolls over black; that, asked to fill in a human figure with the color of their own skin they frequently chose a lighter shade than was accurate, and that they viewed white as good and pretty, but black as bad and ugly.[1] They viewed this as evidence of internalized racism caused by stigmatization.

From a 1984 New York Times interview: "I believed in the 1950s that a significant percentage of Americans were looking for a way out of the morass of segregation. It was wishful thinking."

"It took me 10 to 15 years to realize that I seriously underestimated the depth and complexity of Northern racism. ... In the South, you could use the courts to do away with separate toilets and all that nonsense. We haven’t found a way of dealing with discrimination in the North."